Pedro A. García - Academia.edu (original) (raw)

Papers by Pedro A. García

Research paper thumbnail of Removal of a mixture of veterinary medicinal products by adsorption onto a Scenedesmus almeriensis microalgae-bacteria consortium

Journal of Water Process Engineering, 2021

The adsorption of the veterinary medicinal products (VMP) tetracycline (TET), ciprofloxacin (CIP)... more The adsorption of the veterinary medicinal products (VMP) tetracycline (TET), ciprofloxacin (CIP), sulfadiazine (SDZ) and sulfamethoxazole (SMX) onto a dried Scenedesmus almeriensis microalgae-bacteria consortium was studied at several equilibrium concentrations (20 to 1000 μg/L). Scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR) analysis were performed to investigate the surface morphology of the microalgae and to identify the effect of the antibiotics´functional groups on the surface of the consortium of S. almeriensis and bacteria. Ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) was used to determine the feasibility of this consortium for the removal of antibiotics via biosorption. Freundlich and Langmuir adsorption models were used for the mathematical description of the adsorption equilibrium. Pseudo-first order and pseudo-second order kinetic models were applied to fit the biosorption experimental data. Relative antibiotic removal was higher at low equilibrium concentrations. In the range of the initial VMP concentration studied, ciprofloxacin and tetracycline exhibited the highest removal efficiency of 43-100% and 75-82%, respectively. Likewise, ciprofloxacin and tetraciclyne presented the highest adsorption rates of 0.11-26.66 and 1.78-27.09 mg⋅μg − 1 ⋅h − 1 , respectively. This study revealed that the S. almeriensis-bacteria consortium has a high biosorption power and proved that biosorption is an important mechanism in the removal of ciprofloxacin and tetraciclyne using a microalgae-based water treatment process. However, sulfadiazine and sulfamethoxazole removals did not exceed 32%.

Research paper thumbnail of Quantitative analysis of methane monooxygenase (MMO) explains process robustness in continuous and feast-famine bioreactors treating methane

Chemosphere, Jan 18, 2018

The ability of methanotrophs to rapidly respond to intentional or accidental stress conditions ca... more The ability of methanotrophs to rapidly respond to intentional or accidental stress conditions caused by operational failures or process fluctuations is of utmost importance to guarantee the robustness of CH abatement biotechnologies. In this study, the performance of a continuous and two feast-famine (5:5 days feast-famine cycles) stirred tank reactors treating diluted CH emissions (4-5% v/v) was comparatively assessed for 149 days. The robustness of the three bioreactors towards a 5 days CH deprivation episode was thoroughly evaluated at a molecular level (pmoA gene expression level) and correlated to macroscopic process performance. The bioreactors recovered their steady-state abatement performance (in terms of CH elimination capacity and CO production rate) within 1.5-2 h following CH supply resumption concomitantly with a maximum in pmoA gene expression, regardless of the previous operational mode. However, while methanotrophs from the continuous unit maintained higher basal le...

Research paper thumbnail of Assessing carbon and nitrogen removal in a novel anoxic–aerobic cyanobacterial–bacterial photobioreactor configuration with enhanced biomass sedimentation

Water Research, 2014

The carbon and nitrogen removal potential of an innovative anoxic-aerobic photobioreactor configu... more The carbon and nitrogen removal potential of an innovative anoxic-aerobic photobioreactor configuration operated with both internal and external recyclings was evaluated under different cyanobacterial-bacterial sludge residence times (9-31 days) during the treatment of wastewaters with low C/N ratios. Under optimal operating conditions, the two-stage photobioreactor was-/NO 2 recycling.

Research paper thumbnail of Study of drying systems for the utilization of biodegradable municipal solid wastes as animal feed

Waste Management, 2006

The eVectiveness of diVerent drying systems used for the dehydration of certain fractions of biod... more The eVectiveness of diVerent drying systems used for the dehydration of certain fractions of biodegradable municipal solid wastes with a high moisture content (fruit and vegetable remains) was analyzed. Some tests using small amounts of the material were carried out in natural and forced convection ovens. For larger quantities of wastes, a discontinuous cabinet dryer and a continuous rotary dryer were used. With these dryers, the moisture content was reduced from 800 to 100 g kg ¡1. It was veriWed that the continuous rotary dryer was the most eYcient type of equipment studied, since it allowed a dried waste to be obtained with better nutritional and microbiological qualities and in accordance to the speciWcations of the products for animal feeding.

Research paper thumbnail of Evolución en el diseño de metodologías de enseñanza-aprendizaje para la adquisición de competencias en título de Ingeniero Químico

… docente: docencia y …, 2008

Información del artículo Evolución en el diseño de metodologías de enseñanza-aprendizaje para la ... more Información del artículo Evolución en el diseño de metodologías de enseñanza-aprendizaje para la adquisición de competencias en título de Ingeniero Químico.

Research paper thumbnail of Nitrification-denitrification of UASB effluents highly loaded with nitrogen in an activated sludge reactor operated with short cycled aeration

Water Science and Technology, 2001

A conventional activated sludge reactor operated with short cycled aeration was used for total ni... more A conventional activated sludge reactor operated with short cycled aeration was used for total nitrogen removal of UASB anaerobic reactor effluent containing nitrogen (up to 1,200 mg NKT/L) and organic matter (up to 2,000 mg COD/L). Initially the reactor was fed with synthetic water to progressively introduce the UASB effluent. This favored the acclimation of the microorganisms to the real environment. The results obtained throughout this study showed that initially the tested technology is feasible and can report significant cuts on operation and maintenance when compared to conventional activated sludge processes. Total nitrogen removal up to 66% was attained treating the effluent of an UASB process designed for treating the wastewater of a potato starch factory. Total nitrogen removal capacities ranging between 0.1 and 0.58 kg of nitrogen per cubic metre per day are reported. Short-cycled aeration allowed for a more efficient use of the oxygen supply for nitrification and the org...

Research paper thumbnail of Combining the biological nitrogen and sulfur cycles in anaerobic conditions

Water Science and Technology, 2001

The biochemical processes involved in the anaerobic degradation of carbon, nitrogen and sulfur co... more The biochemical processes involved in the anaerobic degradation of carbon, nitrogen and sulfur compounds can be represented by an oxidation-reduction or electron donor-acceptor scheme. The theoretic values of Gibbs free energy (ΔG0) calculated from thermodynamic data indicate the feasibility of the reactions. The interactions C-S and C-N are well known but there is a lack of information about the interaction N-S. The anaerobic transformation of nitrates using reduced sulfur compounds can be explained considering that nitrate acts as electron acceptor while reduced sulfur compounds are the electron donors. A new N-S interaction in anaerobic conditions (ORP = -425 mV) has been experimentally observed when treating industrial wastewater rich in organic nitrogen and sulfate. The mass balances of the different nitrogenous and sulfur compounds in the liquid and gas phases clearly indicated an uncommon evolution. An important percentage of the nitrogen entering the reactor as TKN was remov...

Research paper thumbnail of Sodium lauryl ether sulfate (SLES) degradation by nitrate-reducing bacteria

Applied microbiology and biotechnology, Jan 15, 2017

The surfactant sodium lauryl ether sulfate (SLES) is widely used in the composition of detergents... more The surfactant sodium lauryl ether sulfate (SLES) is widely used in the composition of detergents and frequently ends up in wastewater treatment plants (WWTPs). While aerobic SLES degradation is well studied, little is known about the fate of this compound in anoxic environments, such as denitrification tanks of WWTPs, nor about the bacteria involved in the anoxic biodegradation. Here, we used SLES as sole carbon and energy source, at concentrations ranging from 50 to 1000 mg L(-1), to enrich and isolate nitrate-reducing bacteria from activated sludge of a WWTP with the anaerobic-anoxic-oxic (A(2)/O) concept. In the 50 mg L(-1) enrichment, Comamonas (50%), Pseudomonas (24%), and Alicycliphilus (12%) were present at higher relative abundance, while Pseudomonas (53%) became dominant in the 1000 mg L(-1) enrichment. Aeromonas hydrophila strain S7, Pseudomonas stutzeri strain S8, and Pseudomonas nitroreducens strain S11 were isolated from the enriched cultures. Under denitrifying condit...

Research paper thumbnail of Tecnología anaerobia en depuración de aguas residuales

Research paper thumbnail of Aerobic treatment of leachates

Journal of Environmental Science and Health . Part A: Environmental Science and Engineering and Toxicology, 1996

The results of aerobic treatment by means of an activated sludge process of leachates from urban ... more The results of aerobic treatment by means of an activated sludge process of leachates from urban solid wastes landfill are shown. The COD of the influent fluctuated from 4000 to 6000 mg/L and the ammonia nitrogen concentration ranged from 100 to 500 mg N‐NH4+/L. The percentage of organic removal was higher than 91% and the ammonia nitrogen removal had a

Research paper thumbnail of Aplicación de reactores de lecho fluidizado en desnitrificación biológica

Research paper thumbnail of Parámetros de operación en sistemas de eliminación de nutrientes

Research paper thumbnail of Simultaneous removal of organic matter, total nitrogen and phosphorous in a single continuous flow activated sludge reactor operated with short aeration cycles

Research paper thumbnail of Influence of substrate feed patterns on biofilm development in anaerobic fluidized bed reactors (AFBR)

Process Biochemistry, 2005

A study of the influence of carbon source composition on microbial biofilm development under meso... more A study of the influence of carbon source composition on microbial biofilm development under mesophilic conditions was carried out on two pilot lab scale anaerobic fluidized bed reactors (AFBR) fed with synthetic wastewater. The first AFBR was fed with acetic acid as sole carbon source while the second AFBR was fed with wastewater containing a mixture of acetic acid, propionic

Research paper thumbnail of Sulfide removal by moderate oxygenation of anaerobic sludge environments

Bioresource Technology, 2007

Introduction of a limited amount of oxygen to anaerobic bioreactors is proposed as a simple techn... more Introduction of a limited amount of oxygen to anaerobic bioreactors is proposed as a simple technique to lower the level of sulfide in the biogas. This paper presents the results of a bioreactor study and of batch experiments that were performed to obtain better insight into the fate of sulfur compounds and oxygen during micro-aerobic sulfide oxidation. Introduction of a low airflow (0.7-0.9 m(3)m(-3)d(-1), corresponding to an O(2)/S molar ratio of 8-10) to a fluidized bed reactor fed with low-sulfate vinasse was sufficient to reduce the biogas H(2)S-content to an undetectable level. Sulfide was initially oxidized to elemental sulfur, thiosulfate and - most probably - polysulfide. Significant sulfate production did not occur. Bioreactor sludge sampled from the reactor after three weeks' micro-aerobic operation was much faster in oxidizing sulfur than bioreactor sludge sampled during fully anaerobic reactor operation. The reaction proceeded faster with increasing O(2)/sulfide ratios.

Research paper thumbnail of Anaerobic treatment of cheese-production wastewater using a UASB reactor

Bioresource Technology, 1991

Research paper thumbnail of Reactores biológicos de lecho fluidizado

INGENIERIA QUIMICA-MADRID-, 2002

Research paper thumbnail of Current Concentrations of Zn, Cu, and As in Piggery Wastewater Compromise Nutrient Removals in Microalgae–Bacteria Photobioreactors Due to Altered Microbial Communities

Biology

The treatment of pig manure is a major environmental issue, and photobioreactors containing conso... more The treatment of pig manure is a major environmental issue, and photobioreactors containing consortia of microalgae and bacteria have proven to be a promising and sustainable treatment alternative. This work studies the effect of Cu, Zn and As, three toxic elements frequently present in piggery wastewater, on the performance and microbiome of photobioreactors. After dopage with Zn (100 mg/L), Cu (100 mg/L), and As (500 µg/L), the high biomass uptake of Zn (69–81%) and Cu (81–83%) decreased the carbon removal in the photobioreactors, inhibited the growth of Chlorella sp., and affected heterotrophic bacterial populations. The biomass As uptake result was low (19%) and actually promoted microalgae growth. The presence of Cu and As decreased nitrogen removal, reducing the abundance of denitrifying bacterial populations. The results showed that metal(loid)s significantly affected 24 bacterial genera and that they did not recover after exposure. Therefore, this study makes an important co...

Research paper thumbnail of Dataset of the article: "Technology validation of photosynthetic biogas upgrading in a semi-industrial scale algal-bacterial photobioreactor

Excel document that contains the data of the article: 'Technology validation of photosyntheti... more Excel document that contains the data of the article: 'Technology validation of photosynthetic biogas upgrading in a semi-industrial scale algal-bacterial photobioreactor'. This dataset shows the values obtained during the experimental period and it complements the corresponding article.

Research paper thumbnail of Evaluation of pretreatments for solubilisation of components and recovery of fermentable monosaccharides from microalgae biomass grown in piggery wastewater

Chemosphere, 2021

Microalgae-bacteria biomass cultured in wastewater is an interesting renewable material capable o... more Microalgae-bacteria biomass cultured in wastewater is an interesting renewable material capable of metabolising nutrients from wastes into carbohydrates, proteins, and lipids through photosynthesis. Despite the interest in the valorisation of this biomass to improve the viability of microalgae-based wastewater treatment processes, very scarce research has been devoted to the fractional recovery of its components. This work evaluates the effect of different pretreatments coupled with enzymatic hydrolysis on the solubilisation of biomass components and on the recovery of fermentable monosaccharides (glucose and xylose) from Scenedesmaceae based biomass grown in a thin layer reactor feed with piggery wastewater. Chemical pretreatments generated high concentrations of byproducts, mainly organic acids. No bacterial DNA was found in these pretreated biomasses. The acid pretreatment provided the highest carbohydrate solubilisation (98%) and monosaccharide recovery (81%). Enzymatic hydrolysis coupled with alkaline NaOH 2 M pretreatment achieved almost complete solubilisation of the biomass components, but high carbohydrate losses. Physical pretreatments remarkably increased the solubilisation of the biomass components during the enzymatic hydrolysis step, especially bead milling, which achieved solubilisation yields of 83% of carbohydrates, 43% of proteins, and 60% of lipids. The presence of viable bacteria in these pretreated biomasses could be related to the high carbohydrate losses and the generation of methanol and ethanol in addition to organic acids as byproducts.

Research paper thumbnail of Removal of a mixture of veterinary medicinal products by adsorption onto a Scenedesmus almeriensis microalgae-bacteria consortium

Journal of Water Process Engineering, 2021

The adsorption of the veterinary medicinal products (VMP) tetracycline (TET), ciprofloxacin (CIP)... more The adsorption of the veterinary medicinal products (VMP) tetracycline (TET), ciprofloxacin (CIP), sulfadiazine (SDZ) and sulfamethoxazole (SMX) onto a dried Scenedesmus almeriensis microalgae-bacteria consortium was studied at several equilibrium concentrations (20 to 1000 μg/L). Scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR) analysis were performed to investigate the surface morphology of the microalgae and to identify the effect of the antibiotics´functional groups on the surface of the consortium of S. almeriensis and bacteria. Ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) was used to determine the feasibility of this consortium for the removal of antibiotics via biosorption. Freundlich and Langmuir adsorption models were used for the mathematical description of the adsorption equilibrium. Pseudo-first order and pseudo-second order kinetic models were applied to fit the biosorption experimental data. Relative antibiotic removal was higher at low equilibrium concentrations. In the range of the initial VMP concentration studied, ciprofloxacin and tetracycline exhibited the highest removal efficiency of 43-100% and 75-82%, respectively. Likewise, ciprofloxacin and tetraciclyne presented the highest adsorption rates of 0.11-26.66 and 1.78-27.09 mg⋅μg − 1 ⋅h − 1 , respectively. This study revealed that the S. almeriensis-bacteria consortium has a high biosorption power and proved that biosorption is an important mechanism in the removal of ciprofloxacin and tetraciclyne using a microalgae-based water treatment process. However, sulfadiazine and sulfamethoxazole removals did not exceed 32%.

Research paper thumbnail of Quantitative analysis of methane monooxygenase (MMO) explains process robustness in continuous and feast-famine bioreactors treating methane

Chemosphere, Jan 18, 2018

The ability of methanotrophs to rapidly respond to intentional or accidental stress conditions ca... more The ability of methanotrophs to rapidly respond to intentional or accidental stress conditions caused by operational failures or process fluctuations is of utmost importance to guarantee the robustness of CH abatement biotechnologies. In this study, the performance of a continuous and two feast-famine (5:5 days feast-famine cycles) stirred tank reactors treating diluted CH emissions (4-5% v/v) was comparatively assessed for 149 days. The robustness of the three bioreactors towards a 5 days CH deprivation episode was thoroughly evaluated at a molecular level (pmoA gene expression level) and correlated to macroscopic process performance. The bioreactors recovered their steady-state abatement performance (in terms of CH elimination capacity and CO production rate) within 1.5-2 h following CH supply resumption concomitantly with a maximum in pmoA gene expression, regardless of the previous operational mode. However, while methanotrophs from the continuous unit maintained higher basal le...

Research paper thumbnail of Assessing carbon and nitrogen removal in a novel anoxic–aerobic cyanobacterial–bacterial photobioreactor configuration with enhanced biomass sedimentation

Water Research, 2014

The carbon and nitrogen removal potential of an innovative anoxic-aerobic photobioreactor configu... more The carbon and nitrogen removal potential of an innovative anoxic-aerobic photobioreactor configuration operated with both internal and external recyclings was evaluated under different cyanobacterial-bacterial sludge residence times (9-31 days) during the treatment of wastewaters with low C/N ratios. Under optimal operating conditions, the two-stage photobioreactor was-/NO 2 recycling.

Research paper thumbnail of Study of drying systems for the utilization of biodegradable municipal solid wastes as animal feed

Waste Management, 2006

The eVectiveness of diVerent drying systems used for the dehydration of certain fractions of biod... more The eVectiveness of diVerent drying systems used for the dehydration of certain fractions of biodegradable municipal solid wastes with a high moisture content (fruit and vegetable remains) was analyzed. Some tests using small amounts of the material were carried out in natural and forced convection ovens. For larger quantities of wastes, a discontinuous cabinet dryer and a continuous rotary dryer were used. With these dryers, the moisture content was reduced from 800 to 100 g kg ¡1. It was veriWed that the continuous rotary dryer was the most eYcient type of equipment studied, since it allowed a dried waste to be obtained with better nutritional and microbiological qualities and in accordance to the speciWcations of the products for animal feeding.

Research paper thumbnail of Evolución en el diseño de metodologías de enseñanza-aprendizaje para la adquisición de competencias en título de Ingeniero Químico

… docente: docencia y …, 2008

Información del artículo Evolución en el diseño de metodologías de enseñanza-aprendizaje para la ... more Información del artículo Evolución en el diseño de metodologías de enseñanza-aprendizaje para la adquisición de competencias en título de Ingeniero Químico.

Research paper thumbnail of Nitrification-denitrification of UASB effluents highly loaded with nitrogen in an activated sludge reactor operated with short cycled aeration

Water Science and Technology, 2001

A conventional activated sludge reactor operated with short cycled aeration was used for total ni... more A conventional activated sludge reactor operated with short cycled aeration was used for total nitrogen removal of UASB anaerobic reactor effluent containing nitrogen (up to 1,200 mg NKT/L) and organic matter (up to 2,000 mg COD/L). Initially the reactor was fed with synthetic water to progressively introduce the UASB effluent. This favored the acclimation of the microorganisms to the real environment. The results obtained throughout this study showed that initially the tested technology is feasible and can report significant cuts on operation and maintenance when compared to conventional activated sludge processes. Total nitrogen removal up to 66% was attained treating the effluent of an UASB process designed for treating the wastewater of a potato starch factory. Total nitrogen removal capacities ranging between 0.1 and 0.58 kg of nitrogen per cubic metre per day are reported. Short-cycled aeration allowed for a more efficient use of the oxygen supply for nitrification and the org...

Research paper thumbnail of Combining the biological nitrogen and sulfur cycles in anaerobic conditions

Water Science and Technology, 2001

The biochemical processes involved in the anaerobic degradation of carbon, nitrogen and sulfur co... more The biochemical processes involved in the anaerobic degradation of carbon, nitrogen and sulfur compounds can be represented by an oxidation-reduction or electron donor-acceptor scheme. The theoretic values of Gibbs free energy (ΔG0) calculated from thermodynamic data indicate the feasibility of the reactions. The interactions C-S and C-N are well known but there is a lack of information about the interaction N-S. The anaerobic transformation of nitrates using reduced sulfur compounds can be explained considering that nitrate acts as electron acceptor while reduced sulfur compounds are the electron donors. A new N-S interaction in anaerobic conditions (ORP = -425 mV) has been experimentally observed when treating industrial wastewater rich in organic nitrogen and sulfate. The mass balances of the different nitrogenous and sulfur compounds in the liquid and gas phases clearly indicated an uncommon evolution. An important percentage of the nitrogen entering the reactor as TKN was remov...

Research paper thumbnail of Sodium lauryl ether sulfate (SLES) degradation by nitrate-reducing bacteria

Applied microbiology and biotechnology, Jan 15, 2017

The surfactant sodium lauryl ether sulfate (SLES) is widely used in the composition of detergents... more The surfactant sodium lauryl ether sulfate (SLES) is widely used in the composition of detergents and frequently ends up in wastewater treatment plants (WWTPs). While aerobic SLES degradation is well studied, little is known about the fate of this compound in anoxic environments, such as denitrification tanks of WWTPs, nor about the bacteria involved in the anoxic biodegradation. Here, we used SLES as sole carbon and energy source, at concentrations ranging from 50 to 1000 mg L(-1), to enrich and isolate nitrate-reducing bacteria from activated sludge of a WWTP with the anaerobic-anoxic-oxic (A(2)/O) concept. In the 50 mg L(-1) enrichment, Comamonas (50%), Pseudomonas (24%), and Alicycliphilus (12%) were present at higher relative abundance, while Pseudomonas (53%) became dominant in the 1000 mg L(-1) enrichment. Aeromonas hydrophila strain S7, Pseudomonas stutzeri strain S8, and Pseudomonas nitroreducens strain S11 were isolated from the enriched cultures. Under denitrifying condit...

Research paper thumbnail of Tecnología anaerobia en depuración de aguas residuales

Research paper thumbnail of Aerobic treatment of leachates

Journal of Environmental Science and Health . Part A: Environmental Science and Engineering and Toxicology, 1996

The results of aerobic treatment by means of an activated sludge process of leachates from urban ... more The results of aerobic treatment by means of an activated sludge process of leachates from urban solid wastes landfill are shown. The COD of the influent fluctuated from 4000 to 6000 mg/L and the ammonia nitrogen concentration ranged from 100 to 500 mg N‐NH4+/L. The percentage of organic removal was higher than 91% and the ammonia nitrogen removal had a

Research paper thumbnail of Aplicación de reactores de lecho fluidizado en desnitrificación biológica

Research paper thumbnail of Parámetros de operación en sistemas de eliminación de nutrientes

Research paper thumbnail of Simultaneous removal of organic matter, total nitrogen and phosphorous in a single continuous flow activated sludge reactor operated with short aeration cycles

Research paper thumbnail of Influence of substrate feed patterns on biofilm development in anaerobic fluidized bed reactors (AFBR)

Process Biochemistry, 2005

A study of the influence of carbon source composition on microbial biofilm development under meso... more A study of the influence of carbon source composition on microbial biofilm development under mesophilic conditions was carried out on two pilot lab scale anaerobic fluidized bed reactors (AFBR) fed with synthetic wastewater. The first AFBR was fed with acetic acid as sole carbon source while the second AFBR was fed with wastewater containing a mixture of acetic acid, propionic

Research paper thumbnail of Sulfide removal by moderate oxygenation of anaerobic sludge environments

Bioresource Technology, 2007

Introduction of a limited amount of oxygen to anaerobic bioreactors is proposed as a simple techn... more Introduction of a limited amount of oxygen to anaerobic bioreactors is proposed as a simple technique to lower the level of sulfide in the biogas. This paper presents the results of a bioreactor study and of batch experiments that were performed to obtain better insight into the fate of sulfur compounds and oxygen during micro-aerobic sulfide oxidation. Introduction of a low airflow (0.7-0.9 m(3)m(-3)d(-1), corresponding to an O(2)/S molar ratio of 8-10) to a fluidized bed reactor fed with low-sulfate vinasse was sufficient to reduce the biogas H(2)S-content to an undetectable level. Sulfide was initially oxidized to elemental sulfur, thiosulfate and - most probably - polysulfide. Significant sulfate production did not occur. Bioreactor sludge sampled from the reactor after three weeks' micro-aerobic operation was much faster in oxidizing sulfur than bioreactor sludge sampled during fully anaerobic reactor operation. The reaction proceeded faster with increasing O(2)/sulfide ratios.

Research paper thumbnail of Anaerobic treatment of cheese-production wastewater using a UASB reactor

Bioresource Technology, 1991

Research paper thumbnail of Reactores biológicos de lecho fluidizado

INGENIERIA QUIMICA-MADRID-, 2002

Research paper thumbnail of Current Concentrations of Zn, Cu, and As in Piggery Wastewater Compromise Nutrient Removals in Microalgae–Bacteria Photobioreactors Due to Altered Microbial Communities

Biology

The treatment of pig manure is a major environmental issue, and photobioreactors containing conso... more The treatment of pig manure is a major environmental issue, and photobioreactors containing consortia of microalgae and bacteria have proven to be a promising and sustainable treatment alternative. This work studies the effect of Cu, Zn and As, three toxic elements frequently present in piggery wastewater, on the performance and microbiome of photobioreactors. After dopage with Zn (100 mg/L), Cu (100 mg/L), and As (500 µg/L), the high biomass uptake of Zn (69–81%) and Cu (81–83%) decreased the carbon removal in the photobioreactors, inhibited the growth of Chlorella sp., and affected heterotrophic bacterial populations. The biomass As uptake result was low (19%) and actually promoted microalgae growth. The presence of Cu and As decreased nitrogen removal, reducing the abundance of denitrifying bacterial populations. The results showed that metal(loid)s significantly affected 24 bacterial genera and that they did not recover after exposure. Therefore, this study makes an important co...

Research paper thumbnail of Dataset of the article: "Technology validation of photosynthetic biogas upgrading in a semi-industrial scale algal-bacterial photobioreactor

Excel document that contains the data of the article: 'Technology validation of photosyntheti... more Excel document that contains the data of the article: 'Technology validation of photosynthetic biogas upgrading in a semi-industrial scale algal-bacterial photobioreactor'. This dataset shows the values obtained during the experimental period and it complements the corresponding article.

Research paper thumbnail of Evaluation of pretreatments for solubilisation of components and recovery of fermentable monosaccharides from microalgae biomass grown in piggery wastewater

Chemosphere, 2021

Microalgae-bacteria biomass cultured in wastewater is an interesting renewable material capable o... more Microalgae-bacteria biomass cultured in wastewater is an interesting renewable material capable of metabolising nutrients from wastes into carbohydrates, proteins, and lipids through photosynthesis. Despite the interest in the valorisation of this biomass to improve the viability of microalgae-based wastewater treatment processes, very scarce research has been devoted to the fractional recovery of its components. This work evaluates the effect of different pretreatments coupled with enzymatic hydrolysis on the solubilisation of biomass components and on the recovery of fermentable monosaccharides (glucose and xylose) from Scenedesmaceae based biomass grown in a thin layer reactor feed with piggery wastewater. Chemical pretreatments generated high concentrations of byproducts, mainly organic acids. No bacterial DNA was found in these pretreated biomasses. The acid pretreatment provided the highest carbohydrate solubilisation (98%) and monosaccharide recovery (81%). Enzymatic hydrolysis coupled with alkaline NaOH 2 M pretreatment achieved almost complete solubilisation of the biomass components, but high carbohydrate losses. Physical pretreatments remarkably increased the solubilisation of the biomass components during the enzymatic hydrolysis step, especially bead milling, which achieved solubilisation yields of 83% of carbohydrates, 43% of proteins, and 60% of lipids. The presence of viable bacteria in these pretreated biomasses could be related to the high carbohydrate losses and the generation of methanol and ethanol in addition to organic acids as byproducts.